It seems like we are in a period of time where many of us are not wishing to play by the rules. This is generally a bad idea, because most rules are established to provide protection.

But in financial planning, some rules are silly, wrong or bad. Let's look at them.

One rule is that when you retire, you should have your investments in bonds equal to your age. What a dumb rule. There are so many factors that determine how much you should invest in bonds, that defaulting to something like that is crazy.

You need to understand how much risk you are willing to take, what your income needs are, how long you want your money to last and what prevailing interest rates are. While stock market ups and downs can be nerve-racking, most people's time horizons are long enough that the risk of inflation outweighs the discomfort of volatility.

Generally, a better rule is to keep a couple of years of spending in cash and invest the rest in an appropriately diversified portfolio tilting more to stocks than bonds.

A second perceived rule for retirees is that you should only spend the income that your portfolio provides. This also goes by never spend your principal. Nah. Again, by focusing on just one aspect of your investment profile, you are ignoring many others.

In this environment, if you are only going to spend your portfolio's income, you are going to be forced into investments that are suboptimal or risky such as high-yield bonds, high-dividend paying stocks, or annuities.

While it may make sense to own some of these types of investments, if you are solely focusing on the income these produce, you are missing a host of other potentially more attractive investments.

By only owning high-dividend paying stocks, you are going to be limited to investing in certain categories such as energy, utilities, real estate investment trusts, consumer products, banks. You may want to own some of these, but not an entire portfolio of them.

A better rule is to take an endowment approach like foundations use. Base your income on a percentage of your portfolio rather than the income it produces. As you get older, you can spend a higher percentage.

Why should someone who is 90 be limited to the same percentage spending as someone who is 65?

Here's a third one. Ignore any potential inheritance. If your parents had enough financial success to be in a position to leave you something, why should you pretend this isn't the case?

Depending on the situation, you are falling victim to the myth of conservative assumptions. This would mean that you are not experiencing the things you could today. The point of financial planning is to have an appropriate level of savings and spending. Spending too much is a problem, but spending too little can be as well.

A fourth rule is that homeownership is the key to your financial future. Nope. Depending on your situation, it may or may not be a good thing.

It is hard to believe that real estate prices don't always go up when all you are reading about is this crazy market. But we view homes as use, not investment, assets. Just like there are good reasons to own — sense of community, stability, control — there are also good reasons to rent — costs, responsibility, flexibility.

The current tax advantages of homeownership are not what they were a few years ago, so the calculus between owning or renting has changed.

How about the fifth rule that you should always choose a Roth IRA or Roth 401(k) over traditional IRA's or 401(k)s. Not necessarily.

An advantage of a Roth is that in return for paying tax on the money that goes in, you don't pay taxes on its growth. If you invest $10,000 in a Roth and your money earns 6% a year, you would have $80,000 tax-free in 36 years! Too good to be true. It's true it's good, but not necessarily as great as it seems.

A big advantage of a Roth is that you don't have to take Required Minimum Distributions at age 72, but other than that, it is really simply a tax decision.

If you are in a higher tax bracket when you invested in your Roth than you are when you take it out, it was a bad deal. That means consider state and federal taxes.

If you think this is a great asset for the kids to inherit — it's only if they are in the same or higher tax bracket than you.

While it is usually a good idea to play by the rules, in financial planning, ignoring some of them is quite beneficial.

Ross Levin is the chief executive and founder of Accredited Investors Wealth Management in Edina.